NAME

SYNOPSIS

DESCRIPTION

Git will sometimes need credentials from the user in order to perform
operations; for example, it may need to ask for a username and password
in order to access a remote repository over HTTP. This manual describes
the mechanisms Git uses to request these credentials, as well as some
features to avoid inputting these credentials repeatedly.

REQUESTING CREDENTIALS

Without any credential helpers defined, Git will try the following
strategies to ask the user for usernames and passwords:

If the GIT_ASKPASS environment variable is set, the program
specified by the variable is invoked. A suitable prompt is provided
to the program on the command line, and the user’s input is read
from its standard output.

Otherwise, if the core.askPass configuration variable is set, its
value is used as above.

Otherwise, if the SSH_ASKPASS environment variable is set, its
value is used as above.

Otherwise, the user is prompted on the terminal.

AVOIDING REPETITION

It can be cumbersome to input the same credentials over and over. Git
provides two methods to reduce this annoyance:

Static configuration of usernames for a given authentication context.

Credential helpers to cache or store passwords, or to interact with
a system password wallet or keychain.

The first is simple and appropriate if you do not have secure storage available
for a password. It is generally configured by adding this to your config:

[credential "https://example.com"]
username = me

Credential helpers, on the other hand, are external programs from which Git can
request both usernames and passwords; they typically interface with secure
storage provided by the OS or other programs.

To use a helper, you must first select one to use. Git currently
includes the following helpers:

You may also have third-party helpers installed; search for
credential-* in the output of git help -a, and consult the
documentation of individual helpers. Once you have selected a helper,
you can tell Git to use it by putting its name into the
credential.helper variable.

Find a helper.

$ git help -a | grep credential-
credential-foo

Read its description.

$ git help credential-foo

Tell Git to use it.

$ git config --global credential.helper foo

CREDENTIAL CONTEXTS

Git considers each credential to have a context defined by a URL. This context
is used to look up context-specific configuration, and is passed to any
helpers, which may use it as an index into secure storage.

For instance, imagine we are accessing https://example.com/foo.git. When Git
looks into a config file to see if a section matches this context, it will
consider the two a match if the context is a more-specific subset of the
pattern in the config file. For example, if you have this in your config file:

[credential "https://example.com"]
username = foo

then we will match: both protocols are the same, both hosts are the same, and
the "pattern" URL does not care about the path component at all. However, this
context would not match:

[credential "https://kernel.org"]
username = foo

because the hostnames differ. Nor would it match foo.example.com; Git
compares hostnames exactly, without considering whether two hosts are part of
the same domain. Likewise, a config entry for http://example.com would not
match: Git compares the protocols exactly.

If the "pattern" URL does include a path component, then this too must match
exactly: the context https://example.com/bar/baz.git will match a config
entry for https://example.com/bar/baz.git (in addition to matching the config
entry for https://example.com) but will not match a config entry for
https://example.com/bar.

CONFIGURATION OPTIONS

Options for a credential context can be configured either in
credential.* (which applies to all credentials), or
credential.<url>.*, where <url> matches the context as described
above.

The following options are available in either location:

helper

The name of an external credential helper, and any associated options.
If the helper name is not an absolute path, then the string git
credential- is prepended. The resulting string is executed by the
shell (so, for example, setting this to foo --option=bar will execute
git credential-foo --option=bar via the shell. See the manual of
specific helpers for examples of their use.

If there are multiple instances of the credential.helper configuration
variable, each helper will be tried in turn, and may provide a username,
password, or nothing. Once Git has acquired both a username and a
password, no more helpers will be tried.

If credential.helper is configured to the empty string, this resets
the helper list to empty (so you may override a helper set by a
lower-priority config file by configuring the empty-string helper,
followed by whatever set of helpers you would like).

username

A default username, if one is not provided in the URL.

useHttpPath

By default, Git does not consider the "path" component of an http URL
to be worth matching via external helpers. This means that a credential
stored for https://example.com/foo.git will also be used for
https://example.com/bar.git. If you do want to distinguish these
cases, set this option to true.

CUSTOM HELPERS

You can write your own custom helpers to interface with any system in
which you keep credentials. See the documentation for Git’s
credentials API for details.